检索结果-南通市图书馆

Transport mechanism of eroded sediment particles under freeze-thaw and runoff conditions

Journal of arid Land 2022年第5期14卷 490-501页

作者： WANG Tian LI Peng HOU Jingming TONG Yu LI Jing WANG Feng LI Zhanbin State key laboratory of Eco-hydraulics in Northwest arid Region Xi'an University of TechnologyXi'an 710048China Key Laboratory of National Forestry Administration on Ecological Hydrology and Disaster Prevention in Arid Regions Xi'an University of TechnologyXi'an 710048China

Hydraulic erosion associated with seasonal freeze-thaw cycles is one of the most predominant factors,which drives soil stripping and transportation.In this study,indoor simulated meltwater erosion experiments were used to investigate the sorting characteristics and transport mechanism of sediment particles under different freeze-thaw conditions(unfrozen,shallow-thawed,and frozen slopes)and runoff rates(1,2,and 4 L/min).Results showed that the order of sediment particle contents was silt>sand>clay during erosion process on unfrozen,shallow-thawed,and frozen slopes.Compared with original soils,clay and silt were lost,and sand was deposited.On unfrozen and shallow-thawed slopes,the change of runoff rate had a significant impact on the enrichment of clay,silt,and sand particles.In this study,the sediment particles transported in the form of suspension/saltation were 83.58%–86.54%on unfrozen slopes,69.24%–84.89%on shallow-thawed slopes,and 83.75%–87.44%on frozen slopes.Moreover,sediment particles smaller than 0.027 mm were preferentially transported.On shallow-thawed slope,relative contribution percentage of suspension/saltation sediment particles gradually increased with the increase in runoff rate,and an opposite trend occurred on unfrozen and frozen slopes.At the same runoff rate,freeze-thaw process had a significant impact on the relative contribution percentage of sediment particle transport via suspension/saltation and rolling during erosion process.The research results provide an improved transport mechanism under freeze-thaw condition for steep loessal slopes.

关键词： freeze-thaw runoff conditions erosion process sediment particles transport mechanism

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The response of soil organic carbon to climate and soil texture in China

引用

Frontiers of Earth Science 2022年第4期16卷 835-845页

作者： Yi ZHANG Peng LI Xiaojun LIU Lie XIAO Tanbao LI Dejun WANG State key laboratory Base of Eco-hydraulic Engineering in arid Area Xi’an University of TechnologyXi’an 710048China State key laboratory of national forestry and Grassland administration on ecological hydrology and disaster prevention in arid regions Xi’an 710048China forestry College Jiangxi Agricultural UniversityNanchang 330045China Northwest Surveying Planning and Designing Institute of National Forestry and Grassland AdministrationXi’an 710048China

Soil organic carbon(SOC)plays an essential role in the carbon cycle and global warming mitigation,and it varies spatially in relation to other soil and environmental properties.But the national distributions and the impact mechanisms of SOC remain debated in China.Therefore,how soil texture and climate factors affect the SOC content and the regional differences in SOC content were explored by analyzing 7857 surface soil samples with different land-use.The results showed that the SOC content in China,with a mean value of 11.20 g·kg^(-1),increased gradually from north to south.The SOC content of arable land in each geographical area was lower than in grassland and forest-land.Although temperature also played a specific role in the SOC content,precipitation was the most critical climate factor.The SOC content was positively correlated with the silt and clay content.The lower the temperature,the greater the effect of environmental factors on SOC.In contrast,the higher the temperature,the more significant impact of soil texture on SOC.The regional difference in SOC highlights the importance of soil responses to climate change.Tempera-ture and soil texture should be explicitly considered when predicting potential future carbon cycle and sequestration.

关键词： soil organic carbon climate soil texture land use

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Establishment of a sediment transport capacity equation on loessal slope via experimental investigation

引用

International Journal of Sediment Research 2023年第2期38卷 166-174页

作者： Tian Wang Jingsi Li Jingming Hou Peng Li Shengdong Cheng Feng Wang Wen Wang Zhanbin Li Reinhard Hinkelmann State key laboratory of Eco-hydraulics in Northwest arid Region of China Xi'an University of Technology Chair of Water Resources Management and Modeling of Hydrosystems Department of Civil Engineering Technische Universit at Berlin Shaanxi Province Institute of Water Resources and Electric Power Investigation and Design Key Laboratory of National Forestry Administration on Ecological Hydrology and Disaster Prevention in Arid Regions Xi'an University of Technology

Areliable sediment transport capacity function provides response against challenges of soil erosion prediction on the Loess Plateau of China. The popular sediment transport capacity functions are questionable on loess slopes because the experimental conditions from which they were derived, like bed materials, gentle slopes,and surface roughness, are different from soil erosion processes on the loess slopes. Due to the foregoing uncertainty, a suitable sediment transport capacity function was developed based on a flume experiment investigation. The erodible bed experiment was implemented for five unit width discharges(1.3 × 10-4-3.3 × 10-4m2/s) and ten slopes(5.2%-57.7%). The selected sediment transport capacity equations were tested in an applicability evaluation. The results of this evaluation found that the Govers(1990) function had the best performance(P.O.0.5-2.0= 76%, R2= 0.93, RMSE = 0.03 kg/(m·s)), followed by the Yalin(1963) function(P.O.0.5-2.0= 80%, R2= 0.81, RMSE = 0.05 kg/(m·s)), and finally by the Low(1989) function(P.O.0.5-2.0= 72%,R2= 0.79, RMSE = 0.04 kg/(m·s)), where P.O.0.5-2.0is the percentage of estimated values with logarithmic discrepancies with the measured value between 0.5 and 2.0; R2is the coefficient of determination and RMSE is the roof mean squares error. The cohesive sediment incipient motion velocity is introduced into the Govers(1990) function, and the sediment particle parameter is determined from measured experimental data. The developed sediment transport capacity equation has good performance with predicted values corresponding to measured values(P.O.0.5-2.0= 98%, R2= 0.98, RMSE = 0.006 kg/(m·s)). The research results provide an improved sediment transport capacity function on the basis of experiments for steep loessal slopes.

关键词： Experimental investigation Hydraulic conditions Loessal slope Sediment transport capacity

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Hydrological and sediment connectivity under freeze-thaw meltwater compound erosion conditions on a loessal slope

引用

International Soil and Water Conservation Research 2023年第2期11卷 402-411页

作者： Tian Wang Jingsi Li Jingming Hou Yongyong Ma Peng Li Yu Tong Jing Li Zhanbin Li State key laboratory of Eco-hydraulics in Northwest arid Region of China Xi'an University of TechnologyXi'an710048ShaanxiChina Key Laboratory of National Forestry Administration on Ecological Hydrology and Disaster Prevention in Arid Regions Xian University of TechnologyXi'an 710048ShaanxiChina Shaanxi Province Institute of Water Resources and Electric Power Investigation and Design Xi'an710005ShaanxiChina

Freeze-thaw processes can influence hydrology,soil erosion,and morphological development by altering the connectivity between active pathways of water and sediment transport.Concentrated flow experi-ments were conducted involving frozen,shallow thawed,and unfrozen soil slopes under 1,2,and 4 L/min runoff rates at a temperature of approximately 5℃.In this study,hydrological connectivity was analysed via the simplified hydrological curve and relative surface connection function.Sediment con-nectivity was analysed via the sediment structure connectivity and sediment functional connectivity.Results indicated that hydrological connectivity was greatest on frozen slopes(FS),followed by shallow thawed slopes(STS),and unfrozen slopes(UFS)given a constant flow rate.Hydrological connectivity increased with increasing runoff rate for each freeze-thaw condition.Freezing condition and runoff rate exhibited a positive response to the hydrological connectivity.Sediment structure connectivity increased with increasing runoff rate for each slope condition.The ordering of sediment structure connectivity across freeze-thaw condition was that FS was greater than STS while STS was greater than UFS inde-pendent of flow rate.Sediment functional connectivity included longitudinal,lateral,and vertical con-nectivity components.Sediment longitudinal and vertical connectivity indicated a trend of first increasing and then decreasing under the different runoff rates and freeze-thaw conditions.For a given runoff rate,the ordering of sediment longitudinal and vertical connectivity across freeze-thaw condition was that FS was greater than STS while STS was greater than UFS.Sediment lateral connectivity exhibited a trend of first decreasing and then stabilizing.The ordering of sediment lateral connectivity across freeze-thaw condition was that UFS was greater than STS while STS was greater than FS.FS could more easily reach longitudinal and vertical penetration.Sediment longitudinal and vertical connectivity rates demonstrated increasing trends

关键词： Freeze-thaw Runoff Erosion Structureand functional connectivity Loessal slope

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Freeze–thaw effects on erosion process in loess slope under simulated rainfall

引用

Journal of arid Land 2020年第6期12卷 937-949页

作者： SU Yuanyi LI Peng REN Zongping XIAO Lie ZHANG Hui State key laboratory of Eco-hydraulics in Northwest arid Region of China Xi'an University of TechnologyXi'an 710048China Key Laboratory of National Forestry Administration on Ecological Hydrology and Disaster Prevention in Arid Regions Xi'an 710048China China JIKAN Research Institute of Engineering Investigations and Design Co.Ltd. Xi'an 710048China

Seasonal freeze–thaw processes have led to severe soil erosion in the middle and high latitudes.The area affected by freeze–thaw erosion in China exceeds 13%of the national territory.So understanding the effect of freeze–thaw on erosion process is of great significance for soil and water conservation as well as for ecological engineering.In this study,we designed simulated rainfall experiments to investigate soil erosion processes under two soil conditions,unfrozen slope(UFS)and frozen slope(FS),and three rainfall intensities of 0.6,0.9 and 1.2 mm/min.The results showed that the initial runoff time of FS occurred much earlier than that of the UFS.Under the same rainfall intensity,the runoff of FS is 1.17–1.26 times that of UFS;and the sediment yield of FS is 6.48–10.49 times that of UFS.With increasing rainfall time,rills were produced on the slope.After the appearance of the rills,the sediment yield on the FS accounts for 74%–86%of the total sediment yield.Rill erosion was the main reason for the increase in soil erosion rate on FS,and the reduction in water percolation resulting from frozen layers was one of the important factors leading to the advancement of rills on slope.A linear relationship existed between the cumulative runoff and the sediment yield of UFS and FS(R2>0.97,PFS0.6(72.30μm)>UFS1.2(72.23μm)>substrate(71.23μm)>FS1.2(71.06μm)>FS0.9(70.72μm).During the early stage of the rainfall,the MWD of the FS was relatively large.However,during the middle to late rainfall,the particle composition gradually approached that of the soil substrate.Under different rainfall intensities,the mean soil erodibility(MK)of the FS was 7.22 times that of the UFS.The ratio of the mean regression coefficient C2(MC2)between FS and UFS was roughly correspondent with MK.Therefore,the parameter C2 can be used to evaluate soil erodibility after the appearance of the rills.This article explored the influence mechanism of free

关键词： unfrozen slope(UFS) frozen slope(FS) simulated rainfall soil size selectivity soil erodibility loess hilly region

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of a check dam system on the runoff generation and concentration processes of a catchment on the Loess Plateau

引用

International Soil and Water Conservation Research 2022年第1期10卷 86-98页

作者： Shuilong Yuan Zhanbin Li Li Chen Peng Li Zeyu Zhang Junzheng Zhang Anna Wang kunxia Yu State key laboratory of Eco-hydraulics in Northwest arid Region of China Xi'an University of TechnologyXi'an710048ShaanxiChina Key Laboratory of National Forestry Administration on Ecological Hydrology and Disaster Prevention in Arid Regions Xi'an University of TechnologyXi'an710048ShaanxiChina Desert Research Institute Las VegasNV89012USA Institute of Soil and Water Conservation Investigation and Planning of Shaanxi Province Xi'an710100ShaanxiChina

As an important soil and water conservation engineering measure,more than 100,000 check dams are constructed across the Loess Plateau;these dams play a vital role in reducing floods and sediment in the region.However,the effects of check dams on hydrologic process are still unclear,particularly when they are deployed as a system for watershed soil and water management.This study examined the watershed hydrologic process modulated by the check dam system in a typical Loess Plateau catchment.By simulating scenarios with various numbers of check dams using a distributed physically-based hydro-logical model,the effects of the number of check dams on runoff generation and concentration were analyzed for the study catchment.The results showed that the presence of check dams reduced the peak discharge and the flood volume and extended the flood duration;the reduction effect on peak discharge was most significant among the three factors.The system of check dams substantially decreased the runoff coefficient,and the runoff coefficient reduction rate was greater for rainstorms with shorter return periods than for rainstorms with longer return periods.The check dams increased the capacity of the catchment regulating and storing floods and extended the average runoff concentration time in the catchment that flattened the instantaneous unit hydrograph.This study reveals the influencing mech-anism of check dam system on the watershed hydrological process under heavy rainstorm conditions and provides a theoretical basis for evaluating the effects of numerous check dams on regional hydrology and water resources on the Loess Plateau.

关键词： Check dam system Runoff generation Runoff concentration Instantaneous unit hydrograph Loess Plateau

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Temporal and spatial variation characteristics of extreme precipitation on the Loess Plateau of China facing the precipitation process

引用

Journal of arid Land 2023年第4期15卷 439-459页

作者： ZHANG Yixin LI Peng XU Guoce MIN Zhiqiang LI Qingshun LI Zhanbin WANG Bin CHEN Yiting State key laboratory of Eco-Hydraulic in Northwest arid Region Xi'an University of TechnologyXi'an 710048China key laboratory of national forestry and Grassland administration on ecological hydrology and disaster prevention in arid regions Northwest Survey and Planning Institute of National Forestry and Grassland AdministrationXi'an 710048China State key laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Chinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China

The preceding and succeeding precipitation(PSP)often act together with extreme precipitation(EP),in turn,causing floods,which is an objective component that is often overlooked with regard to summer flood hazards in the arid region of Northwest China.In this study,event-based extreme precipitation(EEP)was defined as continuous precipitation that includes at least one day of EP.We analyzed the spatiotemporal variation characteristics of four EEP types(front EEP,late EEP,balanced EEP,and single day EEP)across the Loess Plateau(LP)based on data acquired from 87 meteorological stations from 1960 to 2019.Precipitation on the LP basically maintained a spatial pattern of"low in the northwest region and high in the southeast region",and EP over the last 10 a increased significantly.The cumulative precipitation percentage of single day EEP was 34%and was dominant for 60 a,while the cumulative precipitation percentage of front,late,and balanced EEP types associated with PSP accounted for 66%,which confirms to the connotation of EEP.The cumulative frequencies of front and late EEP types were 23%and 21%,respectively,while the cumulative frequency of balanced EEP had the lowest value at only 13%.Moreover,global warming could lead to more single day EEP across the LP,and continuous EEP could increase in the northwestern region and decrease in the eastern region in the future.The concept of process-oriented EP could facilitate further exploration of disaster-causing processes associated with different types of EP,and provide a theoretical basis for deriving precipitation disaster chains and construction of disaster cluster characteristics.

关键词： temporal and spatial variation climate change extreme precipitation(EP) event-based extreme precipitation(EEP) Loess Plateau

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of nitrogen addition on plant-soil-microbe stoichio-metry characteristics of different functional group species in Bothriochloa ischemum community

引用

Soil Ecology Letters 2022年第4期4卷 362-375页

作者： ZiWen Zhao YanLi Qin Yang Wu WenJing Chen Sha Xue GuoBin Liu State key laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationNorthwest A&F UniversityYangling 712100China Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China key laboratory of national forestry and Grassland administration on ecological hydrology and disaster prevention in arid regions Xi'an University of TechnologyXi'an 710048China

Nitrogen(N)deposition,the source of N input into terrestrial ecosystems,is exhibiting an increasingly serious impact on the biogeochemical cycle and functional stability of ecosystems.Grasslands are an important component of terrestrial ecosystems and play a key role in maintaining terrestrial ecosystem balance.Therefore,it is critical to understand the effects of nitrogen addition on grassland ecosystems.We conducted gradientN addition experiments(0,3,6,and 9 g N m^(-2)2 y^(-1))for threeyears ingrassland communities with similar site conditions.We utilized four typical herbaceous plants,including the dominant species Bothriochloa ischemum(B.ischemum)and companion species Stipa bungeana(S.bungeana),Artemisia gmelinii(A.gmelinii),and Cleistogenes squarrosa(C.squarrosa),to explore how different plant-soil-microbe systems respond to N addition.Stoichiometric homeostasis analysis demonstrated that both plants and microbes were strictly homeostatic.However,the companion species were found to be more susceptible to P dominant species.Furthermore,aggravated overlap in stoichiometric niches between plant species were observed at the N6 and N9 levels.Vector analysis indicated that the vector angle was>45°regardlessof plant species and N levels,suggesting that there was a strong Plimitation in the rhizosphere microbial community.Variation partitioning analysis revealed that the Composite roots exhibited a greater effect(explaining 34.7% of the variation)on the rhizosphere microbes than on the Gramineae,indicating that there may be more intense nutrient competition in its rhizosphere.Ingeneral,the effects of N addition on species were different a cross functional groups,with a significant positive effect on the Gramineae(B.ischemum,S.bungeana,and C.squarrosa)and a significant negative effecton the Compositae(A.gmelinii),which should be fully considered in the future ecological management and restoration.

关键词： N addition ecological stoichiometry Stoichiometric homeostasis Nutrient limitation Stoichiometric niche Plant-soil-microbe system

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Flood risk assessment of check dams in the Wangmaogou watershed on the Loess Plateau of China

引用

Journal of Mountain Science 2023年第12期20卷 3631-3647页

作者： GAO Ze-chao SHI Peng LI Zhan-bin LI Peng BAI Lu-lu JIA Yi-li CUI Lin-zhou State key laboratory of Eco-hydraulics in Northwest arid Region of China Xi'an University of TechnologyXi'an 710048China Key Laboratory of National Forestry Administration on Ecological Hydrology and Disaster Prevention in Arid Regions Xi'an University of TechnologyXi'an 710048China Northwest Institute of Forest Inventory Planning and DesignNational Forestry and Grassland AdministrationXi’anShaanxi 710041China College of Life and Environmental Science Wenzhou UniversityWenzhou 325035China

Check dams have been widely used in China’s Loess Plateau region due to their effectiveness in erosion and flood control.However,the safety and stability of the check dam decrease with the operation process,which increases the probability of dam failure during flood events and threatens local residents’ life and property.Thus,this study simulated flood process of the check dam failure in the Wangmaogou watershed in Yulin City,Shaanxi Province,China,calculated different types of inundation losses based on the flood inundation area within the watershed,and determined the number of key flood protection check dams by classifying the flood risk levels of the check dams.The results showed that 5 dams in the watershed were subject to overtopping during different rainfall return periods,which was related to their flood discharge capacity.Dam failure flood process showed a rapid growth trend followed by slow decrease,and the time of flood peak advanced with increase in the return period.After harmonization of evaluation scales,the magnitude of flood inundation losses can be ranked as:economic losses(212.409 million yuan) > life losses(10.368 million yuan) > ecological losses(6.433 million yuan).The risk value for both individual dams and the whole dam system decreases as the return period increases.The number of key flood protection check dams in the Wangmaogou watershed was 2,3,3,3,4,and 5 for floods with return periods of 10,20,30,50,100,and 200 years,respectively.The results provided a theoretical basis for the safe operation and risk evaluation of check dams in the Loess Plateau Hills watershed.

关键词： Check dam Return period Flood control risk Dam failure Inundation loss

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

多因素权衡下的国家公园功能分区一一以青海湖国家公园为例

引用

Journal of Geographical Sciences 2022年第10期32卷 1969-1997页

作者：赵力杜鸣溪张炜李从娟刘秋雨康翔周典 School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an 710049China Northwest Surveying Planning Institute of National Forestry and Grassland AdministrationKey Laboratory National Forestry Administration on Ecological Hydrology and Disaster Prevention in Arid RegionsXi’an 710048China School of Public Policy and administration Xi'an Jiaotong UniversityXi’an 710049China School of Horticulture and forestry Central China Agricultural UniversityWuhan 430070China Xinjiang Institute of Ecology and Geography CASUrumqi 830011China Department of Biological Sciences University of Quebec at MontrealMontreal H3C 3P8Canada

Functional zoning is an important mechanism for achieving national park planning and management objective.Better functional zoning is of great significance to the protection of ecosystem legitimacy and integrity,the appropriate utilization of resources,community integration,and feasible management.In the present study,the proposed Qinghai Lake national Park is the research object.Based on the critical goal of ecological protection,the importance of ecosystem service functions and the ecological sensitivities were evaluated.The results showed that the ecosystem service functions and the ecological sensitivity of the whole region are high.Among them,lake,river and wetland as the most strictly protected ecosystems account for the highest proportion.Then this study divided the proposed Qinghai Lake national Park into five functional areas through grid calculations,spatial analysis and multifactor trade-off.The results indicated that the goal of functional zoning for national park is to maximize the overall utility of park protection value and its comprehensive functions based on its spatial units with different functions,management and control requirements.The zoning scheme addresses the lack of sustainable development in Qinghai Lake national Park due to ecological environmental changes and single-resource zoning with resource protection as the primary goal.This study can serve as a reference for spatial functional zoning methods of national land parks,nature reserves and other natural protected areas.

关键词： national park functional zoning interference from human activities multifactor trade-off

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：